There are many places where installation of ice accumulation monitors could be advantageous. By way of example:
At airports, operations personnel could use information from ice accumulation monitors to alert them to unsafe operating conditions caused by ice accumulation on runways;
On highways, information from ice accumulation monitors could actuate signs to alert motorists of dangerous icings, and information from ice accumulation monitors could inform highway department personnel as to where the highways need sanding, salting, and/or ice removal;
On buildings, ice accumulation on roofs could be monitored to indicate when ice removal was needed;
On aircraft wings and other aircraft surfaces, ice accumulation monitors would provide information to warn aircraft operators of unsafe ice buildups; and
On radomes, ice accumulation monitors would activate deicing equipment when ice accumulation is great enough to interfere with reliable operation of the enclosed antennas, or warn personnel when deicing was necessary.
In reference to previously disclosed equipment used to measure ice accumulations, there has been:
Equipment for measuring ice accumulation by analyzing changes in frequency of an oscillating element as ice accumulates on the element. The element generally protrudes from a surface, so the element is susceptible to traffic damage when installed in a roadway. Also because the element protrudes from the surface being monitored, icing conditions on the element may differ from icing conditions on the surface. In another embodiment of such an oscillating element, a protective cap, flat for roadways, accumulates dirt so that this element is not reliable because it does not distinguish between dirt accumulation and ice accumulation;
Equipment for measuring ice accumulation by analyzing changes in the obstruction of light by the formation of ice, with the light channel portions protruding above the surface and thereby being subject to damage by traffic and inaccuracies associated with protruding elements;
Equipment for measuring ice accumulation by analyzing changes in the pressure drop across an orifice, being caused by the formation of ice, with orifice portions protruding above the surface and thereby being subject to damage by traffic and to inaccuracies associated with protruding elements;
Equipment using internal reflections to detect ice formation on a surface, as set forth in U.S. Pat. No. 2,359,787. However, this equipment does not measure the amount of ice accumulated, and does not indicate methods for compensating for interferences from changes in ambient light or for distinguishing the presence of dirt or mud; and
Equipment using internal reflections to detect ice formation on a surface, as set forth in U.S. Pat. No. 3,540,025. However, this equipment uses a series of heating steps followed by removal of the melted ice, to indicate ice formation. Because these melting steps interfere with ice accumulations, continuous measurements of ice accumulation are not practical with this equipment.
The prior equipment is believed not to have been adequate in measuring accumulations of ice and especially inadequate for measuring the continuous accumulation of cracked or otherwise flawed ice.